Cohu PTZ driver/unit,
                  connections for RS232 4-wire.


         Video Encoder                 PTZ unit

===============================================================

RS232 4-wire                        Cohu 3950
communication                          

            Terminal             Terminal HD5
               Rx+ --------------- Tx+
               Rx- --------------- Tx-
               Tx+ --------------- Rx+
               Tx- --------------- Rx-
                   --------------- GND

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                  Cohu PTZ driver/units,
                  connections for RS422.


    Video Encoder        Cohu PTZ unit            Converter

===============================================================

RS422 serial               Cohu                  RS232 To 422
communication                                      Converter

    Terminal             Terminal
       TX+ --------------- RX+  (green)  ---------- RD (A)
       TX- --------------- RX-  (white)  ---------- RD (B)
       RX+ --------------- TX+  (black)  ---------- TD (A)
       RX- --------------- TX-  (red)    ---------- TD (B)
                                (white)  ---------- GND

===============================================================